I've had an A-760x and an A-500x serviced and they are totally different again from previous models and are easier to work on. Rita told me that there's factory updates for the "A" series which will help prolong the life of the units, I think some resistor changes. She also told me that she doesn't see too many of them but when they do come in due to failure, it's usually pretty bad, like whole boards are burnt out.
Klipsch RB 81 II's
Klipsch RC 64 II
Samson SX3200 (750x2 Sub Amp)
Klipsch THX Ultra 2 Subs KW-120 (2)